Abstract: Using sounding data and surface precipitation data of Lhasa station from 2000 to 2010，the 811 times analysis objects are selected，and the sounding figure，sounding parameters and sounding physical quantities in different phases，different states and different intensity of precipitation are studied．The main conclusions are:The atmospheric water vapor content in the morning is higher than in the night in Lhasa，while the atmosphere unstable energy in the night is higher than in the morning．The atmosphere is more warm and humid before the rain shower either in the morning or in the night．Ggenerally，the rain in the night has the hot and dry performance in the high and low levels while the humid and cold performance in the middle level．But the heavy rain in the night has the humid and hot performance in the high and low levels and the dry and cold performance in the middle level．The difference of atmospheric temperature and humidity between the morning and the night in winter is less than in summer．When it snows，the atmospheric stratification curve and dew point curve shows"funnel"shape，which means the air state is wet up and dry down．At the same time this paper gives a different intensity in different seasons meteoric synthetic average T－LnP diagram and convection temperature，dry and warm cap index，specific humidity integral whole layer of crude Richard．Taking into account the atmospheric conditions when no precipitation occurs，this paper also statistics 5103 times without precipitation，gives atmospheric characteristics when no precipitation．